make insert NULL into a timestamp mark the field as having an
explicit value. So that the field won't be assigned the value
again in TABLE::update_default_field()
make Item_func_now_local::save_in_field(timestamp_field) not to go
through MYSQL_TIME - this conversion is lossy around DST change times.
This fixes inserting a default value into a timestamp field.
This change is a backport from 10.0 to 5.5 for:
1. The full patch for:
MDEV-4841 Wrong character set of ADDTIME() and DATE_ADD()
9adb6e991e
2. A small fragment of:
MDEV-5298 Illegal mix of collations on timestamp
03f6778d61
which overrides Item_temporal_hybrid_func::cmp_type(),
and adds a new line into cache_temporal_4265.result.
otherwise we'd need to store sql_mode *per vcol*
(consider CREATE INDEX...) and how SHOW CREATE TABLE would
support that?
Additionally, get rid of vcol::expr_str, just to make sure
the string is always generated and never leaked in the
original form.
* revert part of the db7edfe that moved calculations from
fix_fields to val_str for Item_func_sysconst and descendants
* mark session state dependent functions in check_vcol_func_processor()
* re-run fix_fields for all such functions for every statement
* fix CURRENT_USER/CURRENT_ROLE not to use Name_resolution_context
(that is allocated on the stack in unpack_vcol_info_from_frm())
Note that NOW(), CURDATE(), etc use lazy initialization and do *not*
force fix_fields to be re-run. The rule is:
* lazy initialization is *not* allowed, if it changes metadata (so,
e.g. DAYNAME() cannot use it)
* lazy initialization is *preferrable* if it has side effects (e.g.
NOW() sets thd->time_zone_used=1, so it's better to do it when
the value of NOW is actually needed, not when NOW is simply prepared)
- Force usage of () around complex DEFAULT expressions
- Give error if DEFAULT expression contains invalid characters
- Don't use const_charset_conversion for stored Item_func_sysconf expressions
as the result is not constaint over different executions
- Fixed Item_func_user() to not store calculated value in str_value
MDEV-10134 Add full support for DEFAULT
- Added support for using tables with MySQL 5.7 virtual fields,
including MySQL 5.7 syntax
- Better error messages also for old cases
- CREATE ... SELECT now also updates timestamp columns
- Blob can now have default values
- Added new system variable "check_constraint_checks", to turn of
CHECK constraint checking if needed.
- Removed some engine independent tests in suite vcol to only test myisam
- Moved some tests from 'include' to 't'. Should some day be done for all tests.
- FRM version increased to 11 if one uses virtual fields or constraints
- Changed to use a bitmap to check if a field has got a value, instead of
setting HAS_EXPLICIT_VALUE bit in field flags
- Expressions can now be up to 65K in total
- Ensure we are not refering to uninitialized fields when handling virtual fields or defaults
- Changed check_vcol_func_processor() to return a bitmap of used types
- Had to change some functions that calculated cached value in fix_fields to do
this in val() or getdate() instead.
- store_now_in_TIME() now takes a THD argument
- fill_record() now updates default values
- Add a lookahead for NOT NULL, to be able to handle DEFAULT 1+1 NOT NULL
- Automatically generate a name for constraints that doesn't have a name
- Added support for ALTER TABLE DROP CONSTRAINT
- Ensure that partition functions register virtual fields used. This fixes
some bugs when using virtual fields in a partitioning function
MDEV-9408 CREATE TABLE SELECT MAX(int_column) creates different columns for table vs view
There were three almost identical pieces of the code:
- Field *Item_func::tmp_table_field();
- Field *Item_sum::create_tmp_field();
- Field *create_tmp_field_from_item();
with a difference in very small details (hence the bugs):
Only Item_func::tmp_table_field() was correct, the other two were not.
Removing the two incorrect pieces of the redundant code.
Joining these three functions/methods into a single virtual method
Item::create_tmp_field().
Additionally, moving Item::make_string_field() and
Item::tmp_table_field_from_field_type() from the public into the
protected section of the class declaration, as they are now not
needed outside of Item.
Item_func_hybrid_field_type did not return correct field_type(), cmp_type()
and result_type() in some cases, because cached_result_type and
cached_field_type were set in independent pieces of the code and
did not properly match to each other.
Fix:
- Removing Item_func_hybrid_result_type
- Deriving Item_func_hybrid_field_type directly from Item_func
- Introducing a new class Type_handler which guarantees that
field_type(), cmp_type() and result_type() are always properly synchronized
and using the new class in Item_func_hybrid_field_type.
Added mandatory thd parameter to Item (and all derivative classes) constructor.
Added thd parameter to all routines that may create items.
Also removed "current_thd" from Item::Item. This reduced number of
pthread_getspecific() calls from 290 to 177 per OLTP RO transaction.
MDEV-6789 segfault in Item_func_from_unixtime::get_date on updating table with virtual columns
* prohibit VALUES in partitioning expression
* prohibit user and system variables in virtual column expressions
* fix Item_func_date_format to cache locale (for %M/%W to return the same as MONTHNAME/DAYNAME)
* fix Item_func_from_unixtime to cache time_zone directly, not THD (and not to crash)
* added tests for other incorrectly allowed (in vcols) functions to see that they don't crash
The crash happened because Item_func_monthname was derived from
Item_func_month, so Item_func_monthname::is_null() did not work fine.
Backporting a change from 5.5: Item_func_monthname is now derived from
Item_str_func.
